Introducing ContextSnapshotFactory

context-propagation/src/main/java/io/micrometer/context/ContextExecutorService.java

@@ -154,9 +154,12 @@ public static ExecutorService wrap(ExecutorService service, Supplier<ContextSnap
      * Variant of {@link #wrap(ExecutorService, Supplier)} that uses
      * {@link ContextSnapshot#captureAll(Object...)} to create the context snapshot.
      * @param service the executorService to wrap
+     * @deprecated use {@link #wrap(ExecutorService, Supplier)}
      */
+    @Deprecated
     public static ExecutorService wrap(ExecutorService service) {
-        return new ContextExecutorService<>(service, ContextSnapshot::captureAll);
+        return wrap(service,
+                () -> DefaultContextSnapshotFactory.captureAll(ContextRegistry.getInstance(), key -> true, false));
     }
 
 }

context-propagation/src/main/java/io/micrometer/context/ContextRegistry.java

@@ -122,7 +122,7 @@ public void setValue(V value) {
             }
 
             @Override
-            public void reset() {
+            public void setValue() {
                 resetTask.run();
             }
         });

context-propagation/src/main/java/io/micrometer/context/ContextScheduledExecutorService.java

@@ -79,9 +79,12 @@ public static ScheduledExecutorService wrap(ScheduledExecutorService service, Su
      * Variant of {@link #wrap(ScheduledExecutorService, Supplier)} that uses
      * {@link ContextSnapshot#captureAll(Object...)} to create the context snapshot.
      * @param service the executorService to wrap
+     * @deprecated use {@link #wrap(ScheduledExecutorService, Supplier)}
      */
+    @Deprecated
     public static ScheduledExecutorService wrap(ScheduledExecutorService service) {
-        return new ContextScheduledExecutorService(service, ContextSnapshot::captureAll);
+        return wrap(service,
+                () -> DefaultContextSnapshotFactory.captureAll(ContextRegistry.getInstance(), key -> true, false));
     }
 
 }

context-propagation/src/main/java/io/micrometer/context/ContextSnapshot.java

@@ -24,7 +24,9 @@
 /**
  * Holds values extracted from {@link ThreadLocal} and other types of context and exposes
  * methods to propagate those values.
- *
+ * <p>
+ * Use {@link ContextSnapshotFactory#builder()} to configure a factory to work with
+ * snapshots.
  * <p>
  * Implementations are disallowed to store {@code null} values. If a {@link ThreadLocal}
  * is not set, or it's value is {@code null}, there is no way of distinguishing one from
@@ -34,11 +36,9 @@
  * {@link ContextAccessor#readValues(Object, Predicate, Map)}, and should likewise ignore
  * {@code null} values from {@link ContextAccessor#readValue(Object, Object)}.
  *
- * <p>
- * Use static factory methods on this interface to create a snapshot.
- *
  * @author Rossen Stoyanchev
  * @author Brian Clozel
+ * @author Dariusz Jędrzejczyk
  * @since 1.0.0
  */
 public interface ContextSnapshot {
@@ -72,6 +72,7 @@ public interface ContextSnapshot {
     /**
      * Variant of {@link #setThreadLocals()} with a predicate to select context values by
      * key.
+     * @param keyPredicate selects keys for use when setting {@link ThreadLocal} values
      * @return an object that can be used to reset {@link ThreadLocal} values at the end
      * of the context scope, either removing them or restoring their previous values, if
      * any.
@@ -82,6 +83,7 @@ public interface ContextSnapshot {
      * Return a new {@code Runnable} that sets {@code ThreadLocal} values from the
      * snapshot around the invocation of the given {@code Runnable}.
      * @param runnable the runnable to instrument
+     * @return wrapped instance
      */
     default Runnable wrap(Runnable runnable) {
         return () -> {
@@ -96,6 +98,7 @@ default Runnable wrap(Runnable runnable) {
      * snapshot around the invocation of the given {@code Callable}.
      * @param callable the callable to instrument
      * @param <T> the type of value produced by the {@code Callable}
+     * @return wrapped instance
      */
     default <T> Callable<T> wrap(Callable<T> callable) {
         return () -> {
@@ -110,6 +113,7 @@ default <T> Callable<T> wrap(Callable<T> callable) {
      * snapshot around the invocation of the given {@code Consumer}.
      * @param consumer the callable to instrument
      * @param <T> the type of value produced by the {@code Callable}
+     * @return wrapped instance
      */
     default <T> Consumer<T> wrap(Consumer<T> consumer) {
         return value -> {
@@ -123,6 +127,7 @@ default <T> Consumer<T> wrap(Consumer<T> consumer) {
      * Return a new {@code Executor} that sets {@code ThreadLocal} values from the
      * snapshot around the invocation of any executed, {@code Runnable}.
      * @param executor the executor to instrument
+     * @return wrapped instance
      * @see ContextExecutorService
      * @see ContextScheduledExecutorService
      */
@@ -139,7 +144,10 @@ default Executor wrapExecutor(Executor executor) {
      * instance.
      * @param contexts one more context objects to extract values from
      * @return a snapshot with saved context values
+     * @deprecated use {@link ContextSnapshotFactory#captureAll(Object...)} on a factory
+     * obtained via a {@link ContextSnapshotFactory#builder()}.
      */
+    @Deprecated
     static ContextSnapshot captureAll(Object... contexts) {
         return captureAll(ContextRegistry.getInstance(), contexts);
     }
@@ -151,7 +159,11 @@ static ContextSnapshot captureAll(Object... contexts) {
      * @param registry the registry to use
      * @param contexts one more context objects to extract values from
      * @return a snapshot with saved context values
+     * @deprecated use {@link ContextSnapshotFactory#captureAll(Object...)} on a factory
+     * obtained via a {@link ContextSnapshotFactory#builder()} combined with
+     * {@link ContextSnapshotFactory.Builder#contextRegistry(ContextRegistry)}.
      */
+    @Deprecated
     static ContextSnapshot captureAll(ContextRegistry registry, Object... contexts) {
         return captureAllUsing(key -> true, registry, contexts);
     }
@@ -163,61 +175,23 @@ static ContextSnapshot captureAll(ContextRegistry registry, Object... contexts)
      * @param registry the registry with the accessors to use
      * @param contexts one more context objects to extract values from
      * @return a snapshot with saved context values
+     * @deprecated use {@link ContextSnapshotFactory#captureAll(Object...)} on a factory
+     * obtained via a {@link ContextSnapshotFactory#builder()} and configure
+     * {@link ContextSnapshotFactory.Builder#captureKeyPredicate(Predicate)} and
+     * {@link ContextSnapshotFactory.Builder#contextRegistry(ContextRegistry)}.
      */
+    @Deprecated
     static ContextSnapshot captureAllUsing(Predicate<Object> keyPredicate, ContextRegistry registry,
             Object... contexts) {
-
-        return DefaultContextSnapshot.captureAll(registry, keyPredicate, contexts);
-    }
-
-    /**
-     * Create a {@link ContextSnapshot} by reading values from the given context objects.
-     * <p>
-     * Values captured multiple times are overridden in the snapshot by the order of
-     * contexts given as arguments.
-     * @param contexts the contexts to read values from
-     * @return the created {@link ContextSnapshot}
-     * @since 1.0.3
-     */
-    static ContextSnapshot captureFromContext(Object... contexts) {
-        return DefaultContextSnapshot.captureFromContext(key -> true, ContextRegistry.getInstance(), null, contexts);
-    }
-
-    /**
-     * Create a {@link ContextSnapshot} by reading values from the given context objects.
-     * <p>
-     * Values captured multiple times are overridden in the snapshot by the order of
-     * contexts given as arguments.
-     * @param registry the registry to use
-     * @param contexts the contexts to read values from
-     * @return the created {@link ContextSnapshot}
-     * @since 1.0.3
-     */
-    static ContextSnapshot captureFromContext(ContextRegistry registry, Object... contexts) {
-        return DefaultContextSnapshot.captureFromContext(key -> true, registry, null, contexts);
-    }
-
-    /**
-     * Create a {@link ContextSnapshot} by reading values from the given context objects.
-     * <p>
-     * Values captured multiple times are overridden in the snapshot by the order of
-     * contexts given as arguments.
-     * @param keyPredicate predicate for context value keys
-     * @param registry the registry to use
-     * @param contexts the contexts to read values from
-     * @return the created {@link ContextSnapshot}
-     * @since 1.0.3
-     */
-    static ContextSnapshot captureFromContext(Predicate<Object> keyPredicate, ContextRegistry registry,
-            Object... contexts) {
-        return DefaultContextSnapshot.captureFromContext(keyPredicate, registry, null, contexts);
+        return DefaultContextSnapshotFactory.captureAll(registry, keyPredicate, false, contexts);
     }
 
     /**
      * Create a {@link ContextSnapshot} by reading values from the given context object.
      * @param context the context to read values from
      * @return the created {@link ContextSnapshot}
-     * @deprecated as of 1.0.3 in favor of {@link #captureFromContext(Object...)}
+     * @deprecated use {@link ContextSnapshotFactory#captureFrom(Object...)} on a factory
+     * obtained via a {@link ContextSnapshotFactory#builder()}.
      */
     @Deprecated
     static ContextSnapshot captureFrom(Object context) {
@@ -229,12 +203,13 @@ static ContextSnapshot captureFrom(Object context) {
      * @param context the context to read values from
      * @param registry the registry to use
      * @return the created {@link ContextSnapshot}
-     * @deprecated as of 1.0.3 in favor of
-     * {@link #captureFromContext(ContextRegistry, Object...)}
+     * @deprecated use {@link ContextSnapshotFactory#captureFrom(Object...)} on a factory
+     * obtained via a {@link ContextSnapshotFactory#builder()} combined with
+     * {@link ContextSnapshotFactory.Builder#contextRegistry(ContextRegistry)}.
      */
     @Deprecated
     static ContextSnapshot captureFrom(Object context, ContextRegistry registry) {
-        return DefaultContextSnapshot.captureFromContext(key -> true, registry, null, context);
+        return DefaultContextSnapshotFactory.captureFromContext(key -> true, false, registry, null, context);
     }
 
     /**
@@ -243,12 +218,14 @@ static ContextSnapshot captureFrom(Object context, ContextRegistry registry) {
      * @param keyPredicate predicate for context value keys
      * @param registry the registry to use
      * @return the created {@link ContextSnapshot}
-     * @deprecated as of 1.0.3 in favor of
-     * {@link #captureFromContext(Predicate, ContextRegistry, Object...)}
+     * @deprecated use {@link ContextSnapshotFactory#captureFrom(Object...)} on a factory
+     * obtained via a {@link ContextSnapshotFactory#builder()} and configure
+     * {@link ContextSnapshotFactory.Builder#captureKeyPredicate(Predicate)} and
+     * {@link ContextSnapshotFactory.Builder#contextRegistry(ContextRegistry)}.
      */
     @Deprecated
     static ContextSnapshot captureFrom(Object context, Predicate<Object> keyPredicate, ContextRegistry registry) {
-        return DefaultContextSnapshot.captureFromContext(keyPredicate, registry, null, context);
+        return DefaultContextSnapshotFactory.captureFromContext(keyPredicate, false, registry, null, context);
     }
 
     /**
@@ -258,9 +235,14 @@ static ContextSnapshot captureFrom(Object context, Predicate<Object> keyPredicat
      * @return an object that can be used to reset {@link ThreadLocal} values at the end
      * of the context scope, either removing them or restoring their previous values, if
      * any.
+     * @deprecated use
+     * {@link ContextSnapshotFactory#setThreadLocalsFrom(Object, String...)} with no keys
+     * on a factory obtained via a {@link ContextSnapshotFactory#builder()}.
      */
+    @Deprecated
     static Scope setAllThreadLocalsFrom(Object sourceContext) {
-        return DefaultContextSnapshot.setAllThreadLocalsFrom(sourceContext, ContextRegistry.getInstance());
+        return DefaultContextSnapshotFactory.setAllThreadLocalsFrom(sourceContext, ContextRegistry.getInstance(),
+                false);
     }
 
     /**
@@ -271,9 +253,14 @@ static Scope setAllThreadLocalsFrom(Object sourceContext) {
      * @return an object that can be used to reset {@link ThreadLocal} values at the end
      * of the context scope, either removing them or restoring their previous values, if
      * any.
+     * @deprecated use
+     * {@link ContextSnapshotFactory#setThreadLocalsFrom(Object, String...)} with no keys
+     * on a factory obtained via a {@link ContextSnapshotFactory#builder()} combined with
+     * {@link ContextSnapshotFactory.Builder#contextRegistry(ContextRegistry)}.
      */
+    @Deprecated
     static Scope setAllThreadLocalsFrom(Object sourceContext, ContextRegistry contextRegistry) {
-        return DefaultContextSnapshot.setAllThreadLocalsFrom(sourceContext, contextRegistry);
+        return DefaultContextSnapshotFactory.setAllThreadLocalsFrom(sourceContext, contextRegistry, false);
     }
 
     /**
@@ -286,7 +273,11 @@ static Scope setAllThreadLocalsFrom(Object sourceContext, ContextRegistry contex
      * @return an object that can be used to reset {@link ThreadLocal} values at the end
      * of the context scope, either removing them or restoring their previous values, if
      * any.
+     * @deprecated use
+     * {@link ContextSnapshotFactory#setThreadLocalsFrom(Object, String...)} on a factory
+     * obtained via a {@link ContextSnapshotFactory#builder()}.
      */
+    @Deprecated
     static Scope setThreadLocalsFrom(Object sourceContext, String... keys) {
         return setThreadLocalsFrom(sourceContext, ContextRegistry.getInstance(), keys);
     }
@@ -300,9 +291,14 @@ static Scope setThreadLocalsFrom(Object sourceContext, String... keys) {
      * @return an object that can be used to reset {@link ThreadLocal} values at the end
      * of the context scope, either removing them or restoring their previous values, if
      * any.
+     * @deprecated use
+     * {@link ContextSnapshotFactory#setThreadLocalsFrom(Object, String...)} on a factory
+     * obtained via a {@link ContextSnapshotFactory#builder()} combined with
+     * {@link ContextSnapshotFactory.Builder#contextRegistry(ContextRegistry)}.
      */
+    @Deprecated
     static Scope setThreadLocalsFrom(Object sourceContext, ContextRegistry contextRegistry, String... keys) {
-        return DefaultContextSnapshot.setThreadLocalsFrom(sourceContext, contextRegistry, keys);
+        return DefaultContextSnapshotFactory.setThreadLocalsFrom(sourceContext, contextRegistry, false, keys);
     }
 
     /**